Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Wed Aug 17, 2011 12:07 pm

by russp81

I have a few questions. I did some calculations at work today and determined that 24 lb/hr injectors will support up to 768 HP. To come to this number I used the PE of gasoline ~ 49.1 HP-hours (125,000 BTU/gal). I figured out the "limiting" time for the intake stroke assuming I red-line it at 6700 RPM, which comes out to 70.1 ms if you do the math to account for 180 degreez of the 720 degrees of crank rotation to figure out how long the intake stroke takes at 6700 RPM. Using that number, it is possible in theory, using a 24 lb/hr injector to inject .00731 ounces of fuel into the cylinder if held open for the entire duration of 70.1 ms. So, that math leads to the 768 HP if you use the standard assumption that 65% of that power is transferred as mechanical energy (not heat). I realize that this number is "ideal" and I won't be able to hold the injector open for the entire stroke, but it sure seems as though I'd be in the ball park if I'm looking to get 500 HP out of 24 lb/hr injectors. Am I missing something?

I just built my setup (shown in my sig), and I see that lots of people buy bigger fuel pumps and injectors and that makes perfect sense to me if you're still using the factory ECU, it has no idea you have a bigger injector / higher fuel pressure, etc...so in a way aren't those methods sort of "band-aids"?

Also, I chose not to buy the FMU / BTM / Tuner module that comes with the supercharger because again aren't those just band-aids? Doesn't having MS allow me to tune / tweak the existing equipement?

I'm just making sure I'm not missing something, because I've yet to see a post about a 500 HP machine using the factory fuel pump / smaller injectors, etc...

It seems to me that I can hold a smaller injector open for a longer period of time and get the same effect of pulsing a 42 lb/hr injector within the bounds of the factory ECU parameters.

I want to make sure I'm not out in left field before I start driving this thing around and leaning it out and learning the hard way. I do have O2 monitoring so that makes me a little more comfortable, but I could sure use some feedback on whether or not my reasoning is correct. Thanks guys!

BTW, I will definitely share all of my learnings, msq's, etc...as I go along. I look forward to the discussions / learnings!

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Wed Aug 17, 2011 12:10 pm

by russp81

Basically, I already have 24 lb/hr injectors and I'd like to avoid dropping $300 or so to get bigger ones, if that wasn't evident by my last post!

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Sat Aug 20, 2011 4:08 am

by boostdcoupe

nevermind...

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Sat Aug 20, 2011 8:23 am

by a73camaro

If you have 16 injectors you will be about to support 700 HP. Eight injectors at 24 lb/hr will only support 350 HP.

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Sat Jan 21, 2012 2:48 pm

by jkmoffitt

I have a procharged 89 coupe running 5/6psi with 42# injectors, stock 302, and 255 pump. I am running MS2Extra with the latest firmware. I plan on using your latest tune as a base, I assume its going to be way rich given your after market H/C/I. Feel free to email me at jkmoffitt88@aol.com with any advice. I have spent the last week or so reading as much as I can and asking around on the forums for help. At times I feel like I'm going in circles! I would PM you but I do not have the privileges.

Thanks!

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Sun Jan 22, 2012 4:34 am

by 92notch

My tune is a good starting point for you will be alittle rich
But that us ok. Guve it a shot. One thing is before you roll out
Make sure the timing in tuberstudio matches the timing on the balancer.
My email address is mustangnotch92@yahoo.com if you have any
More questions

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Thu Mar 08, 2012 5:44 am

by rdclark123

92notch,
I would love to get ahold of your n/a before you booosted. we have around the same mods and this ms2 is kickin my butt. i also plan to boost the car so i will be checking out your tune you posted. i didn't see where you posted your n/a tune before the turbo.
thanks alot

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Fri Mar 09, 2012 5:53 am

by 92notch

it is the same tune as my Turbo tune only think different was that i added cells at the top in the spark and ve maps for boost you will be able to run fine on that. But i will try to dig up my old tune. i will keep you posted

Re: 92 Mustang 306,TFS H/I/C 42lbinjectors ,255fuel pump Tur

Posted: Tue Feb 12, 2013 11:33 am

by gixxerpro

Hello, Im building an 88 Mustang with a Lightning 351 windsor with the following parts: X303 roller cam, ported GT40 heads and intake, Pony down turbo hot side with a Turbonetics T70 ball bearing turbo with a newgen w/g and raptor b.o.v. blowing through an ebay intercooler. I have new fuel rails and set of f.a.s.t. 47.5 lb an hour fuel injectors. Fuel pumps are walbro 255's in tank and inline. I have an innovate MSBC-1 boost control. I am considering a megasquirt kit now and would like to hear your up and down stories about your install. I would also like to get a copy of your tune. My name is Tony and my email is gixxerproo@yahoo.com. I look forward to hearing from you. Thanks a lot for your time.